Some important achievements obtained in the latest research phase for a project named as "Rocky desertification and adaptive ecosystem regulation in Karst mountain region, Southwest China" under the National Basic Research Program of China
Under the leadership of Professor Congqiang LIU, director of the Institute of Geochemistry Chinese Academy of Sciences and chief scientist of a project named as "Rocky desertification and adaptive ecosystem regulation in Karst mountain region, Southwest China" under the National Basic Research Program of China (also called 973 Program), project researchers have achieved some good results in the latest phase in 2008 through their hard work together.
According to the planned tasks and aims of this research project in 2008, main researches are concentrated on studying the relationship between climate change and the evolution of the ecosystem in the Karst area, the parameters for evaluating dangerous level of soil erosion in the Karst region, the characteristics and controlling factors of the cycling (releasing) of fertilizers in the rock-soil erosion process by utilizing the geological documentary records in the Karst mountain region, Southwest China, in order to construct ecological hydrological model in many dimensions and to discuss species optimizational collocation in the Karst area. Some important results have been obtained in the latest phase.
The temporal-spatial evolution process of the rocky desertification has been discussed and the information system of the rocky desertification in the Karst area has been established by project researchers through analyzing the variation of population, utilization of cultivated land, variation of demanded foods, and the introducing and popularizing fine varieties in history of Guizhou Province, and using mathematical model of spatial variation. Some new progresses have been achieved in terms of the construction of indexes for comprehensively evaluating rocky desertification and the research on geological background of the rocky desertification. It is discovered that the productivity of soil by weathering of carbonates in the Karst area in Guizhou Province is closely associated with the lithology of strata, structure and landforms. The thickness of soil produced by the weathering of carbonates in the research area has been calculated by using the empirical value. It is discovered that chemical degradation, biological degradation and zymohydrolysis are three ways for the weathering of carbonates by biomass. It is demonstrated that the process of carbonate weathering is experienced three geochemical stages in terms of enriching in Si and Al and depleting in Ca and Mg, enriching in Fe and Mn, and enriching in Al and depleting in Si respectively. A large amount of geological evidences of pedogenesis from the weathering of carbonates have been obtained and the pedogenic mechanism has been revealed. The soil-forming ages have been studied and the pedogenic rate from the weathering of carbonates has been discussed. The age of weathering residuum of carbonates in Guizhou has been obtained by using the un-equilibrium radioactive uranium series method. The distribution characteristics of 137Cs in karst slope soils have been studied. The losing rate of surface soils in a small rocky desertification karst area has been studied by using 137Cs tracing method. Micro-mechanism of soils under the arid-wet circulation effect has been studied.
The creepy experiment of soils inside and outside of caves in the rocky desertification regions and their relationship to the lose of water-soils have been studied. The chemical erosion intensity of the mountain land in the Hogfenghu lake drainage area and the circulation of bio-ecosystem factors of the small drainage area in the central Guizhou have been studied. The study on the dynamic coupling mechanism of the water consumption and the ecological and hydrological processes of the typical karst vegetations in various times has been carried out. A calculating model on the intensity of evaporating water in soils has been established. A systematic study has been carried on the characteristics of component of air input matters and their bio-geochemical circulation in the drainage area, the bio-geochemical process of the karst soil-vegetation interaction and the circulation of nutrition elements, the relationship among the erosion, geology and the variation of ecosystem in the karst drainage area. The photosynthesis mechanism of the adaptability of lianas to the karst area has been discussed. The characteristics of water-maintaining texture of the superior woody plants in karst forests and their relationship to the effectiveness of long term water utilization have been discussed. It is testified that the local plants in the rocky desertification karst area have strong self-rehabilitation capability. The adaptabilities of two main spices of superior plants to the demand of water have been comparatively studied. The capability of fast growth, the stress resistance, adaptability to the karst environment and the easy invasibility of Broussonetia papyrifera have been explained. 639 data records have been added into the database of the distribution and importance of the clone plants and non-clone plants distributed in the karst area and the non-karst area. The experiment on the importance of clonal integration to the branch of the bushes (Sarcococca ruscifolia Stapf ) in the special karst environment has been carried out. The living rates, morphological indexes, and the biomass of varieties have been measured. The wild Camellia crassicolumna and var. multiplex have been selected to carry out the experiment of the interaction between cells of tea leaves and rocks, with reference of the planted tea and the Puer tea. The biomass and distribution pattern of biocoenosis have been studied by regression analysis and yielding analysis. A method for testing soil available phosphorous has been designed on the basis of image analysis and its patent has been obtained and published. Based on the researches on the relationship among the biocoenosis texture, biodiversity characteristics and biocoenosis productivity, the analysis of productivity maintaining mechanism of the karst rocky desertification ecosystem and biocoenosis stability, the analysis of the temporal-special variation of the plant biomass and productivity, and the studies on the vulnerability, local stability, reversible denaturation, and transition of the karst rocky desertification ecosystem, the mechanism and path of the adaptive rehabilitation of the karst rocky desertification ecosystems have been further discussed. On the hand of optimization, adjustment and control of the service functions of the karst eco-system, researches are mainly concentrated on the ecosystem function zone and the vegetation distribution pattern of the karst peak cluster depression area, the biocoenosis characteristics and influence of vegetation rehabilitation by the species regeneration and interference way in the mixed evergreen and deciduous broadleaved forest in northwest Guangxi, the status evaluation and outlook prediction of the sustainable development of the karst region, the analysis of the sensibility of the rocky desertification of the Hechi area, the evaluation of ecosystem service function of the karst region and the ecosystem functional regionalization, the adaptable landscape ecology design for the peak cluster depression area, etc.
On the basis of the above research work, some good achievements at this latest phase of this project have been obtained. A second-level award of the Science and technology Progress Award of Guizhou Province is obtained, a monograph named as “The bio-geochemical process and the cycling of surficial materials – the nutrients cycling of the soil-vegetation ecosystem in the karst region, southwest China” has been published, and the biomass and its special variation of the forestry in Guizhou karst area have been estimated by using the existing forestry survey data.
In 2008, the members of this project have published 37 SCI papers, 11 EI papers, 111 CSCD papers, and 12 important conference papers, obtained 4 patents, and completed the annual research plan. Comparing to the achievements obtained in 2007, the qualities are improved and the quantities are increased in terms of the published papers, the obtained patents, and the trained research students in 2008.（Nan Junya original Zhang Xunchun translation）